I've seen one game where any shields were only allowed to be one layer of cardboard thick, and you were only allowed one for the whole twenty-four hours. The few that has a shield lost them very quickly because they were Swiss-cheesed. The year before they had plywood shields with gun holes and windows in them. Four guys would move together as a wall, and they had a medic with them. If you hit one of them, they'd all hunker down together, medic back in, and then continue on. There was a rule that grenades would stop riot shields, but they never called those hits. Eventually we set a trap for them. Led them under a sniper's watch in the dark (a big hole in the cement wall of a building), and sprayed them about the top of their heads mercilessly. Then their shields went missing....somehow. Weird eh?
From a realism standpoint they don't make a lot of sense. There's the weight thing, but taking consecutive rounds close range will either deplete your shield or knock you on your butt.
From a sports perspective they make less sense. Really an unsportsmanlike tool, almost as bad as not calling your hits. If you need a shield, why are you playing?
ďREALITY IS LIKE A STONE. TO MANY ITíS HARD AND COLD, THEY CANíT HUG IT OR EAT IT, IT ONLY FRUSTERATES THEM AND DOESNíT DO THEM MUCH GOOD. TO OTHERS ITíS STRONG AND DEPENDABLE, YOU CAN BUILD WITH IT, BUILD UPON IT, OR WORK WITH IT, ALSO USE IT TO SMASH PEOPLE IN THE FACE.Ē